Bovine dehorning: assessing pain and providing analgesic management.

Dehorning or disbudding in cattle is performed for a variety of reasons using various methods. Pain associated with this procedure has been mostly evaluated through behavioral, physiologic, and neuroendocrine changes following dehorning. Analgesics, including local nerve blockades, anti-inflammatories, and opioids have demonstrated an effective attenuation of the cortisol response. The administration of sedatives with analgesic properties has been indicated in the attenuation of the acute phase of pain associated with dehorning. Following a literature review, this article recommends a multimodal approach to analgesia for dehorning procedures, including the use of a local anesthetic and anti-inflammatory and, when possible, a sedative-analgesic.

Pharmacokinetics and physiologic effects of intramuscularly administered xylazine hydrochloride-ketamine hydrochloride-butorphanol tartrate alone or in combination with orally administered sodium salicylate on biomarkers of pain in Holstein calves following castration and dehorning.

OBJECTIVE: To determine the pharmacokinetic parameters of xylazine, ketamine, and butorphanol (XKB) administered IM and sodium salicylate (SAL) administered PO to calves and to compare drug effects on biomarkers of pain and distress following sham and actual castration and dehorning. ANIMALS: 40 Holstein bull calves from 3 farms. PROCEDURES: Calves weighing 108 to 235 kg (n = 10 calves/group) received one of the following treatments prior to sham (period 1) and actual (period 2) castration and dehorning: saline (0.9% NaCl) solution IM (placebo); SAL administered PO through drinking water at concentrations from 2.5 to 5 mg/mL from 24 hours prior to period 1 to 48 hours after period 2; butorphanol (0.025 mg/kg), xylazine (0.05 mg/kg), and ketamine (0.1 mg/kg) coadministered IM immediately prior to both periods; and a combination of SAL and XKB (SAL+XKB). Plasma drug concentrations, average daily gain (ADG), chute exit velocity, serum cortisol concentrations, and electrodermal activity were evaluated. RESULTS: ADG (days 0 to 13) was significantly greater in the SAL and SAL+XKB groups than in the other 2 groups. Calves receiving XKB had reduced chute exit velocity in both periods. Serum cortisol concentrations increased in all groups from period 1 to period 2. However, XKB attenuated the cortisol response for the first hour after castration and dehorning and oral SAL administration reduced the response from 1 to 6 hours. Administration of XKB decreased electrodermal activity scores in both periods. CONCLUSIONS AND CLINICAL RELEVANCE: SAL administered PO through drinking water decreased cortisol concentrations and reduced the decrease in ADG associated with castration and dehorning in calves.